JP2002180104A - Cylinder sleeve, and cylinder block for internal- combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder sleeve where bonding property can be improved by the increase of the area of bonding between the inner peripheral surface of a sleeve and a plating layer and the heat of combustion gas applied to the plating layer can be rapidly dissipated by the increase of heat transfer area and, as a result, peeling of the plating layer can be practically prevented. SOLUTION: Aluminum alloy powder of 20-100 μm average particle size is solidified with the addition of 15-38 wt.% silicon (Si). The sleeve 3 is formed by using a material obtained by solidifying and extruding the rapidly solidified powder, and initial-crystal silicon (Si) of <=20 μm average particle size is formed. After alkali etching treatment is applied to the inner peripheral surface of the sleeve 3, plating is applied. Then the sleeve is disposed within a cylinder main body 2a made of aluminum-alloy casting to constitute a cylinder block 2 for internal-combustion engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cylinder sleeve and a cylinder block for an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine, a sleeve made of aluminum alloy is mounted on a cylinder body made of aluminum alloy casting.
There is a type provided with a cylinder block for an internal combustion engine manufactured by casting, press-fitting, or shrink-fitting and applying predetermined plating to the inner surface of the sleeve. When plating is performed on the inner periphery of the sleeve in this manner, the oxide film on the surface is removed, and the bonding of the plating layer to the inner peripheral surface of the sleeve is improved.

[0003]

However, the conventional sleeve member uses a material such as 12Si-3Cu-aluminum material, and the oxide film can be removed by etching, but the surface is smooth. As a result, the bonding of the plating layer to the inner peripheral surface of the sleeve could not be further improved.

The present invention has been made in view of such circumstances, and it is possible to increase the bonding area between the inner peripheral surface of the sleeve and the plating layer to further improve the bonding property, and to increase the heat transfer area to increase the plating area. It is an object of the present invention to provide a cylinder sleeve and a cylinder block for an internal combustion engine, which can quickly radiate the heat of the combustion gas added to the layer and hardly cause peeling of the plating layer.

[0005]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to the first aspect of the present invention, a sleeve is formed by using a rapidly solidified powder solidified extrusion forming material having a chemical composition of 15 to 38% by weight of silicon (Si) added to a sleeve base material. A cylinder sleeve characterized in that an inner peripheral surface of the sleeve is subjected to an alkali etching treatment and then plated. ].

According to the first aspect of the present invention, a material obtained by solidifying and extruding a rapidly solidified powder having a sleeve base material having a silicon (Si) content of 15 to 38% by weight is used. Since the particle size can be made sufficiently small, the deposition of the plating is not hindered in the alkaline etching step which is a pretreatment of the plating, and the adhesion of the plating is secured.

According to a second aspect of the present invention, there is provided a cylinder block for an internal combustion engine in which a sleeve made of aluminum alloy is arranged in a cylinder body made of aluminum alloy casting. Containing silicon (Si), the silicon (Si) being primary crystal silicon (Si) having an average particle size of 20 μm or less;
A cylinder block for an internal combustion engine, wherein an inner peripheral surface of the sleeve is subjected to an alkali etching treatment and then plated. ].

According to the second aspect of the present invention, the aluminum alloy constituting the sleeve contains silicon (Si), and the silicon (Si) is converted into primary crystal silicon (Si) having an average particle size of 20 μm or less, By performing alkali etching on the inner peripheral surface of the sleeve, silicon (Si) on the inner peripheral surface of the sleeve is removed by alkali etching,
Irregularities are formed on the inner peripheral surface of the sleeve, and silicon (S
i) Since the average particle diameter of the particles is small, fine irregularities can be formed densely, the bonding area between the inner peripheral surface of the sleeve and the plating layer increases, and the bonding property can be further improved, and the anchor effect due to the irregularities is reduced. In addition, the heat transfer area increases due to the increase in the coupling area, the heat of the combustion gas added to the plating layer can be quickly radiated, and the plating layer hardly peels off.

According to a third aspect of the present invention, there is provided a method as described above, wherein the aluminum alloy forming the sleeve contains one piece of silicon (Si).
The cylinder block for an internal combustion engine according to claim 2, wherein the content is 5 to 38% by weight. ].

According to the third aspect of the present invention, the aluminum alloy forming the sleeve contains one silicon (Si).
By containing 5 to 38% by weight, the silicon (Si) content is large and the average particle size of the silicon (Si) particles is small, so that finer irregularities can be formed densely, and the inner peripheral surface of the sleeve and the plating layer can be formed. And the bonding area can be further improved.

According to a fourth aspect of the present invention, there is provided a cylinder block for an internal combustion engine according to the second aspect, wherein the sleeve is formed by coagulating and solidifying an aluminum alloy powder having an average particle diameter of 20 to 100 μm. . ].

According to the fourth aspect of the present invention, by forming the sleeve by agglomerating and solidifying an aluminum alloy powder having an average particle diameter of 20 to 100 μm, finer irregularities can be formed densely, and the inner periphery of the sleeve can be formed. The bonding area between the surface and the plating layer is increased, and the bonding property can be further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a cylinder sleeve and a cylinder block for an internal combustion engine according to the present invention will be described below with reference to the drawings.

The present invention is applied to a water-cooled or air-cooled four-stroke internal combustion engine and a two-stroke internal combustion engine having a cylinder block for an internal combustion engine, and the sleeve is applied to a wet or dry structure.

FIG. 1 is a sectional view of a water-cooled four-stroke internal combustion engine, and FIG. 2 is a sectional view taken along the line II-II of FIG.

FIGS. 1 and 2 show an example of this internal combustion engine.
1 shows a water-cooled four-cycle internal combustion engine having a dry-type sleeve, but the present invention is not limited to this embodiment.

As the four-cycle engine 1 of the vehicle, an in-line four-cylinder engine is used. The cylinder block 2 of the four-cycle engine 1 includes a cylinder body 2a and a sleeve 3, and a piston 4 is provided on the sleeve 3 so as to be able to reciprocate. The reciprocating motion of the piston 4 rotates a crankshaft (not shown) disposed in the crank chamber 7 via the connecting rod 5. The cylinder block 2 is provided with a cylinder head 6, which is fastened and fixed to the cylinder block 2 by bolts 8. The piston 4 is provided with a piston ring 4b. A head cover 80 is provided on the cylinder head 6.

A combustion chamber 12 is formed by the sleeve 3 of the cylinder block 2, the head 4a of the piston 4, and the cylinder head 6. An ignition plug 86 is attached to the cylinder head 6 so as to face the combustion chamber 12.

The cylinder head 6 has an intake passage 13.
And an exhaust passage 14, and a collective intake pipe 15 is connected to the intake passage 13. A collective exhaust pipe 16 is connected to the exhaust passage 14.

The opening of the intake passage 13 facing the combustion chamber 12 is opened and closed by an intake valve 18, and the opening of the exhaust passage 14 facing the combustion chamber 12 is opened and closed by an exhaust valve 19. Tappets 30, 31 of the intake valve 18 and the exhaust valve 19 have camshafts 32, 33, respectively.
Cams 32a, 33a are in contact with each other, and the camshafts 32, 3
3, the cams 32a, 33a cause the tappet 30,
The intake valve 18 and the exhaust valve 19 are pushed via 31, thereby opening and closing the intake passage 13 and the exhaust passage 14.

A water jacket 20 is formed on the cylinder body 2a of the cylinder block 2.
, A water jacket 21 is formed in the cylinder head 6. The surroundings of the combustion chamber 12 are cooled by the cooling water of the water jackets 20 and 21, and the sleeve 3 has a dry structure.

FIG. 3 shows a water-cooled four-stroke internal combustion engine having a wet-type sleeve, in which cooling water around a combustion chamber 12 is cooled by cooling water in a water jacket 20, and the sleeve 3 is directly cooled by cooling water. I have. An O-ring 85 is provided under the water jacket 20 between the cylinder body 2a and the sleeve 3 for sealing.

Next, the manufacture of a cylinder block for an internal combustion engine will be described. FIG. 4 is a diagram showing a manufacturing process of a cylinder block for an internal combustion engine.

A rapidly solidified powder material is formed (step S).
1) The rapidly solidified powder material is cold isostatically pressed to form a sleeve material (a billet) (step S2) and vacuum-sintered (step S3). Thereafter, heating and hot extrusion is performed to form a hollow hollow material, and the material is cooled (step S4). If necessary, heat treatment is performed, and the sleeve hollow material is cut and processed (step S5) to form the sleeve 3. The sleeve 3 is cast in the cylinder body 2a (step S6), annealed (step S7), plated (step S8), and subjected to honing (step S9).

As the rapidly solidified powder material in step S1, for example, an ingot of an aluminum alloy containing silicon (Si), iron (Fe) and other components is prepared for a base material of aluminum (A1). About 7
Dissolve at 00 ° C or higher, then spray in mist and cool at a cooling rate of 1
By rapidly cooling and solidifying at a temperature of 00 ° C./sec or more, it is formed as a rapidly solidified powder (powder metal) of an aluminum alloy.

As an aluminum alloy powder material for forming a sleeve material (a billet), for example, silicon (S) having an average grain size of primary silicon of 20 μm or less is used.
A rapidly solidified powder of an aluminum alloy containing i) in the range of 15 to 38% by weight is used.

As a rapidly solidified powder of such an aluminum alloy, aluminum (Al) is used as a base material, silicon (Si) is 15 to 38% by weight, iron (Fe) is contained in the whole.
1.5% by weight or less, copper (Cu) 6.8% by weight or less,
0.2 to 2% by weight of magnesium (Mg), 1.5% by weight or less of manganese (Mn), 0.4% by weight of chromium (Cr)
% Or less, and zinc (Zn) in a range of 0.3% by weight or less.

In the rapidly solidified powder of the aluminum alloy having the Si content increased to 15 to 38% by weight based on the aluminum alloy of the 2000 series or 6000 specified in JIS, silicon (S
i) is added in order to increase wear resistance and seizure resistance by crystallizing hard primary crystals and eutectic silicon grains in the metal structure. Iron (Fe) disperses and strengthens the metal structure. 20
Copper (Cu) and magnesium (Mg) are added to obtain high strength at 0 ° C. or higher, and are added to increase the strength at 200 ° C. or lower. In the above range, desired wear resistance and seizure resistance and required strength at high temperature can be obtained.

In the sleeve material in which the rapidly solidified powder of the aluminum alloy is solidified as described above, the molten aluminum alloy is sprayed in a mist state and rapidly solidified, whereby the aluminum alloy powder has an average particle size. Approximately 20 to 100 μm, and silicon (Si) contained therein is hard primary crystal silicon (S) crystallized in a metal structure of an aluminum alloy which solidifies while powdering.
i) is finely divided so as to have an average particle diameter of 20 μm or less, and is dispersed for each aluminum alloy particle.

In step S2, the rapidly solidified powdered material of the aluminum alloy is placed in a mold having an opening in one or more directions, and the plunger is inserted into the mold through the opening while bleeding air. While maintaining the mold and the mold in a water-tight state, a hydrostatic press is applied to apply a hydrostatic pressure to the plunger, and the rapidly solidified powder material is solidified.

In step S3, the pre-solidified rapidly solidified powder material is placed in a sintering mold, and the inside of the mold is evacuated and heated and pressurized to form a denser solid mass substantially free of air. Is done.

In step S4, the solid mass is accommodated in the extrusion die, heated, extruded from the die portion of the extrusion die into a hollow round bar shape, that is, a hollow element shape, cut at the cooled portion, and cut into a predetermined length of hollow. It is a round bar. In addition,
In step S4, the hardness of the extruded and cooled sleeve hollow material is set to a Rockwell hardness (HRB) of 40.
The parameters in the process are adjusted so as to be as described above.

In step S5, the sleeve is cut to the length of the sleeve material, and the inner and outer shape and the end are processed to form a cast-in sleeve.

In step S6, the sleeve 3 is cast into the cylinder main body 2a by cylinder die casting in which the sleeve 3 is cast. In this case, the sleeve 3 is housed in a mold, and a part of the inner periphery of the sleeve is supported by a supporting member, and a molten metal of a predetermined aluminum alloy is poured into a gap between the mold and the outer periphery of the sleeve. This is done by guiding at high pressure. Then, machining of each part of the cylinder block 2 and the cylinder bore is performed.

By forming irregularities on the outer peripheral surface of the sleeve before casting the sleeve, even if the fastening force is reduced due to a difference in the coefficient of thermal expansion between the base material and the sleeve during operation, the sleeve can be reliably prevented from coming off. . Such irregularities on the outer peripheral surface of the sleeve can artificially form fine cracks by adjusting molding conditions such as extrusion speed and temperature when extruding a billet. It is also possible to use shot blast. In addition to shot blasting, it can be formed by other machining or pickling (etching) of the entire sleeve. Further, instead of a method of forming irregularities on the outer periphery of the sleeve by shot blasting or the like to enhance the bonding property with the base material, the sleeve and the base material may be bonded by using low melting point solder to prevent the sleeve from coming off. .

Here, the shot blast means that the particle size is 50.
１５０150 μm steel balls, carbide beads, stainless steel balls, zinc beads, glass beads, river sand containing a lot of quartz having a slightly larger particle size, etc., with a projector, for example, 40 to 80 m /
This means that a workpiece is projected at a projection speed of s.

In step S7, annealing is performed.
The hardness of the sleeve 3 after the annealing is defined as Rockwell hardness (H
RB) The heat treatment conditions are adjusted so as to be 40 or more.

The plating process in step S8 is plating of the inner surface of the sleeve. Basically, the plating process includes a pretreatment including a degreasing process, an alkali etching process, and a mixed acid etching process, an alumite process as a base process, and a composite plating process. It consists of two steps, and a water washing process is performed after each step.

In the water washing process, two separate water tanks are used for each step, and the entire cylinder block is sequentially immersed in the two water tanks and moved up and down to remove the processing liquid in the previous step. The water in the aquarium is regularly replaced with fresh clean water. After each washing process, move to the next step as soon as possible, perform the next process with a water film on the surface,
It is possible to prevent dust and the like from adhering to the processing section and direct contact with oxygen in the air to prevent the formation of an oxide film and the like, thereby improving the reliability of processing in a later step.

Then, the above plating process (step S8)
After that, the plating layer on the inner peripheral surface of the sleeve is subjected to honing by honing (step S9), and the thickness of the plating film is preferably about 50 μm, and in some cases, 20 μm to 1 μm.
00 μm and the surface roughness of the plating layer is 1.0 μm.
mRz or less. As a result, the surface of the plating layer can be surely smoothed, the coefficient of friction at the time of sliding of the piston 4 and the piston ring 4b can be reduced, and the retention of engine oil is improved and lubricity is improved. be able to. In addition, Rz is B0 of JIS standard.
601.

In the embodiment of the present invention, a cylinder block 2 for an internal combustion engine in which a sleeve 3 made of aluminum alloy is cast in a cylinder body 2a made of aluminum alloy casting.
However, they may be arranged by press fitting or shrink fitting.

A conventional extruded material is used for the sleeve base material. The extruded material has a relatively low silicon content, and its coefficient of thermal expansion is equal to or less than that of the aluminum casting material of the surrounding cylinder body. When manufacturing the cylinder block, when the sleeve base material is cast by the aluminum die casting, a gap is generated between the sleeve base material and the aluminum casting in a process of solidification of the casting material. The accuracy at the time of inner diameter grinding in the process may deteriorate, and the presence of the gap further deteriorates the shape such as the cylindricity and roundness of the sleeve because the thermal conductivity partially deteriorates, This causes an increase in oil consumption and a deterioration in performance.

As described above, when the silicon (Si) content is 15
It is effective to use an aluminum alloy casting with a content of about 38% by weight so as not to form a gap between the sleeve base material and the aluminum casting. However, in a normal casting material, primary crystal Si grains are several tens μm or more. Therefore, even if an attempt is made to form a plating layer on the surface, adhesion is poor and not only peeling of plating may occur during processing but also sufficient durability such as peeling of plating during operation cannot be obtained.

For this reason, the sleeve 3 has an average particle size of 20 to 1
The silicon (Si) having an average particle diameter of 20 μm was formed by coagulating and solidifying an aluminum alloy powder of 00 μm.
The following primary crystal silicon (Si) is used. In the alkali etching step, which is a pretreatment for plating, the silicon (Si) particle size is sufficiently small as 20 μm or less.
-Deposition of P plating is not hindered. For this reason, the adhesion of plating can be ensured.

As described above, the aluminum alloy constituting the sleeve 3 contains silicon (Si), and the silicon (Si) is converted into primary crystal silicon (Si) having an average particle diameter of 20 μm or less. (Si) on the inner peripheral surface of the sleeve by alkali etching
Is removed by alkali etching to form irregularities on the inner peripheral surface of the sleeve, and since the average particle size of the silicon (Si) particles is small, fine irregularities can be formed densely. The bonding area can be increased to further improve the bonding property, and there is an anchor effect due to the unevenness. Further, the increase in the bonding area increases the heat transfer area, and quickly dissipates the heat of the combustion gas added to the plating layer. Possible,
Hardly causes peeling of plating layer.

Further, by containing 15 to 38% by weight of silicon (Si) in the aluminum alloy constituting the sleeve 3, the silicon (Si) content is large and the average particle size of the silicon (Si) particles is small. Therefore, finer irregularities can be formed densely, and the bonding area between the inner peripheral surface of the sleeve and the plating layer increases, so that the bonding property can be further improved.

As described above, the aluminum alloy constituting the sleeve 3 is made of silicon (Si) of 15 to 3 times.
8% by weight, and the coefficient of linear expansion of the sleeve 3 is 15 to 2
2 (at 200 ° C.), which is smaller than the linear expansion coefficient of the cylinder body 2a (for example, the linear expansion coefficient of the aluminum alloy ADC12 for JIS die casting is 20 (at 200 ° C.)
The coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a.

Therefore, when the sleeve 3 made of aluminum alloy is cast into the cylinder body 2a of aluminum alloy casting, the molten metal on the cylinder body 2a side surrounds the outer periphery of the sleeve 3, and the sleeve 3 is heated and thermally expanded. As the cylinder body 2a is gradually cooled after being filled with water, the sleeve 3 is also cooled and thermally contracted.
The molten metal on the side a shrinks when solidified by cooling, and further shrinks as the temperature decreases.
5 to 38% by weight, the coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a, and the sleeve tightening force due to solidification shrinkage on the cylinder body 2a side and heat shrinkage after solidification is reduced. Therefore, no gap is formed between the sleeve 3 and the cylinder body 2a.

Also, a sleeve base material is formed by extrusion using a rapidly solidified powder solidified extrusion forming material having a chemical composition of aluminum alloy plus silicon (Si), and the extrusion processing conditions such as extrusion speed and temperature By forming a hollow round bar, a continuous projection parallel to the length direction of 0.1 to 2 mm in height is adjusted, or
By uniformly distributing minute cracks having a depth of 10 μm to 1 mm on the surface and leaving protrusions or small cracks on the outer peripheral surface even after processing into a sleeve, the bonding with the cylinder body 2a is strengthened, In addition, heat transfer can be made uniform.

In the operating state, the temperature of the sleeve 3 is lower than the temperature at the time of casting (a value close to the melting temperature of the aluminum alloy) (air cooling and water cooling are performed.
About 00 ° C. to 300 ° C.) and 15 to 3 pieces of silicon (Si).
8% by weight, the coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a, the sleeve tightening force is maintained, and a gap is generated between the sleeve 3 and the cylinder body 2a. The cylindrical shape and roundness of the inner circumference of the sleeve are maintained, and the heat from the circumferential surface of the sleeve 3 is transferred well to the cylinder body side via the plating layer and the inside of the sleeve 3 body, so that the hot spot is formed. And seizure with the piston 4 can be prevented.

After completion of casting (normal temperature condition), predetermined plating is performed, honing is performed to increase the cylindricity and roundness of the inner circumference of the sleeve 3, and a crankshaft, a piston and the like are mounted on the cylinder block 2. When the internal combustion engine is operated after assembling and further fastening the cylinder head 6 with bolts 8 to complete the assembly as an internal combustion engine, the sleeve 3 thermally expands, and at this time, the cylinder body 2 around the sleeve to which the cylinder head 6 is bolted is bolted. The plurality of bolt holes have increased rigidity and resist thermal expansion. On the other hand, the cylinder body 2a, which is an intermediate portion between the bolt holes on the outer periphery of the sleeve, has low resistance to thermal expansion. And a linear expansion coefficient of the sleeve 3 of the cylinder body 2
a is 10% smaller than the linear expansion coefficient of
Has a small thermal expansion, maintains the cylindricality and roundness of the inner circumference of the sleeve, improves the isolation between the combustion chamber 12 and the crank chamber 7 by the piston ring 4b, increases the oil consumption, and causes the combustion gas to flow through. Fuel economy deterioration and oil deterioration can be prevented.

As an example, JIS is used for the sleeve base material.
2 for basic chemical components of 2000 or JIS 6000 series
A manufacturing process using a rapidly solidified powder solidified extrusion forming material having a chemical composition to which 5% by weight of silicon (Si) was added was manufactured by the process of FIG.

The rapidly solidified powder of an aluminum alloy based on JIS 2000 and containing an amount of silicon (Si) that becomes a hypereutectic composition is based on aluminum (Al) and contains silicon (Si) in the whole. 15-38% by weight,
1.5% by weight or less of iron (Fe) and 1.5% or less of copper (Cu)
6.8 wt%, magnesium (Mg) 1.8 wt% or less, manganese (Mn) 0.2-1.2 wt%, chromium (Cr) 0.1 wt% or less, zinc (Zn) 0 0.3% by weight or less and titanium (Ti) 0.2% by weight or less.

The rapidly solidified powder of an aluminum alloy based on JIS 6000 and to which an amount of silicon (Si) having a hypereutectic composition is added is based on aluminum (Al), and silicon (Si) is contained throughout. 15-38% by weight,
1.0 wt% or less of iron (Fe), 0.4 wt% or less of copper (Cu), 0.35 to 1.5 wt% of magnesium (Mg), 0.8 wt% of manganese (Mn) Hereinafter, chromium (Cr) content is 0.35% by weight or less, and zinc (Zn) 0.2
5% by weight or less and titanium (Ti) 0.15% by weight or less.

In Example 1, JIS 6000-based 6061
Using an extruded material of -25Si rapidly solidified powder solidified powder as a sleeve substrate, Ni-P-SiC dispersed composite plating was applied to the inner surface thereof.

In Example 2, JIS6000-based 6061
+ 2-4Fe-25Si rapidly solidified powder solidified extruded material was used as a sleeve substrate, and Ni-P-SiC dispersed composite plating was applied to the inner surface thereof.

The third embodiment uses 2017 JIS 2000
Alternatively, Ni-P-SiC-dispersed composite plating was applied to the inner surface of the quenched and solidified powder of 20224-25Si as a sleeve substrate.

In this embodiment, the reduction of the oil consumption is an improvement of the cylinder deformation, and attention was paid to the improvement of the sleeve adhesion after casting. In order to improve the adhesion of the sleeve, attention was paid to changing to a sleeve material having a low coefficient of linear expansion, and a material having a low coefficient of linear expansion was selected from an iron-based material, which was lightweight and excellent in heat transfer, and was made an aluminum composite material.

The physical properties and mechanical properties of this sleeve material are compared and shown in Table 1. Table 1 shows a sleeve having a low coefficient of linear expansion aluminum as a base material and a hard film formed on the inner surface.
As shown in FIG.
3Cu aluminum alloy material, cylinder body ADC12
Reduced compared to. Cylinder body AD which is cast-in material
The ratio of C12 to the coefficient of linear expansion was 0.85, and the tightening deformation at the time of casting the sleeve was improved.

[0061]

[Table 1] Further, the interfacial gap at the time of cast-in is reduced as shown in Table 2 by annealing at 250 ° C. × 1 hour followed by cooling. The interface gap between the sleeve and the cylinder body was measured at eight points in the circumferential direction of the sleeve. In the case of the bore No. 4, the mold cooling is stopped as an abnormality.

[0062]

[Table 2] When the interface gap at the time of cast-in decreases, as shown in Table 1,
The Young's modulus of the liner substrate is improved, the roundness and cylindricity of the cylinder after honing are improved, and the followability and sealing performance of the piston ring are improved.

When the interfacial gap at the time of cast-in is reduced,
Uniformity and improvement of heat transfer have been achieved, local deformation during operation has been improved, the roundness and cylindricity of the cylinder after honing have been improved, and the followability and sealability of the piston ring have been improved. The oil consumption was improved.

In the above Examples 1 to 3, extrusion was performed using a rapidly solidified powder solidified extrusion forming material, and the extrusion processing conditions, for example, extrusion speed, temperature, etc., were adjusted, as shown in FIG. A continuous protrusion 100 having a height of 0.1 to 2 mm parallel to the longitudinal direction is formed on the outer surface of the sleeve base material, and the surface has a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material at the maximum. The cracks 101 were uniformly distributed.

FIG. 6 is a diagram showing the relationship between the sleeve surface sharp depth, the sleeve strength, and the interface gap.
μm to 1 mm is the optimum range of the intense depth where the sleeve strength is large and the interface gap can be reduced.
By uniformly distributing the micro cracks 101 of 0 μm to 1 mm, the joining of the casting with the cylinder body 2a can be strengthened and the heat transfer can be uniform.

In Examples 1 to 3, nickel-based dispersion plating containing phosphorus and eutectoids was performed at a high speed, and nickel (Ni) -phosphorus (P) -silicon carbide (SiC) dispersion plating was performed. It is done at high speed,
This Ni-P-SiC dispersion plating has the following properties.

When Ni-P-SiC dispersion plating is applied to the inner peripheral surface of the sleeve 3, the inner peripheral surface of the sleeve 3 is formed as shown in FIG.
The plating film 50 including the Ni-P matrix 51 and the eutectoid particles 52 of SiC as shown in FIG. On the surface of the plating film 50, an oil pocket 53 composed of a honing eye is formed for lubrication (FIG. 7A).
Further, when the sliding of the piston 5 due to the operation is repeated, as shown in FIG. 7B, the hard silicon carbide (S
The eutectoid particles 52 of iC) are left with the Ni-P matrix 5
As a result, the new oil pocket 54 is generated. Therefore, oil lubrication can be favorably performed over a long period of time.

The relationship between the temperature and the plating hardness was examined for Ni-P-SiC dispersed plating, Ni-SiC dispersed plating, and hard chromium plating.
The hardness of the -P-SiC dispersion plating is higher than that of the hard chromium plating, especially when heat-treated at about 350 [deg.] C., and is significantly higher than that of the Ni-SiC dispersion plating containing no phosphorus (P). This indicates that the inclusion of phosphorus increases the hardness after the heat treatment.

In this example, the adhesion of the plating was evaluated by a file test, a drilling test, a heating and quenching test, etc., on a plate-shaped test piece plated. It has been confirmed that it has improved. Further, when an endurance test of the internal combustion engine was performed, the oil consumption was reduced to about 1 /
2 was confirmed, and no trouble such as peeling of the plating occurred at all.

[0070]

As described above, according to the first aspect of the present invention, the silicon (Si) content of the sleeve substrate is reduced to 1%.
By using a material obtained by solidifying and extruding a rapidly solidified powder of 5 to 38% by weight, the silicon (Si) particle size can be made sufficiently small, so that the deposition of plating is inhibited in the alkaline etching step which is a pretreatment for plating. Therefore, the adhesion of plating is ensured.

According to the second aspect of the present invention, the aluminum alloy forming the sleeve contains silicon (Si), and the silicon (Si) is converted to primary crystal silicon (Si) having an average particle size of 20 μm or less, and By performing an alkali etching process on the inner peripheral surface, silicon (Si) on the inner peripheral surface of the sleeve is removed by the alkaline etching process, and irregularities are formed on the inner peripheral surface of the sleeve.
i) Since the average particle diameter of the particles is small, fine irregularities can be formed densely, the bonding area between the inner peripheral surface of the sleeve and the plating layer increases, and the bonding property can be further improved, and the anchor effect due to the irregularities is reduced. In addition, the heat transfer area increases due to the increase in the coupling area, the heat of the combustion gas added to the plating layer can be quickly radiated, and the plating layer hardly peels off.

According to the third aspect of the present invention, silicon (Si) is added to the aluminum alloy constituting the sleeve in an amount of 15 to 15%.
By containing 38% by weight, the silicon (Si) content is large and the average particle size of the silicon (Si) particles is small, so that finer irregularities can be formed densely, and the inner peripheral surface of the sleeve and the plating layer The bonding area is increased, and the bonding property can be further improved.

According to the fourth aspect of the invention, by forming the sleeve by agglomerating and solidifying an aluminum alloy powder having an average particle diameter of 20 to 100 μm, finer irregularities can be formed densely, and the inner peripheral surface of the sleeve is formed The bonding area with the plating layer is increased, and the bonding property can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water-cooled four-stroke internal combustion engine having a dry-type sleeve.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view of a water-cooled four-stroke internal combustion engine having a wet-type sleeve.

FIG. 4 is a view showing a manufacturing process of a cylinder block for an internal combustion engine.

FIG. 5 is a diagram showing a state of an outer surface of a sleeve base material.

FIG. 6 is a diagram showing the relationship between the sleeve surface sharpness depth, the sleeve strength, and the interface gap.

FIG. 7 is a diagram showing Ni—P—SiC dispersed composite plating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-cooled 4-cycle internal combustion engine 2 Cylinder block for internal combustion engines 2a Cylinder main body 3 Sleeve 4 Piston

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 21/02 C22C 21/02 C25D 15/02 C25D 15/02 F F02F 1/00 F02F 1/00 CG F (72) Inventor Takeshi Araki 2500 Shinkai, Iwata-shi, Shizuoka Prefecture Yamaha Motor Co., Ltd. (72) Inventor Daisuke Nakao 2500 Shinkai, Iwata-shi, Shizuoka Prefecture Yamaha Motor Co., Ltd. F-term (reference) 3G024 AA22 AA25 AA26 AA28 FA01 GA02 GA08 GA14 GA16 HA07 HA19 HA20 4K018 AA16 BA08 BD10 EA33 FA14 FA23 HA03 JA34 KA02 KA08

Claims (4)

[Claims] 1. A sleeve is formed using a rapidly solidified powder solidified extrusion forming material having a chemical composition of 15 to 38% by weight of silicon (Si) added to a sleeve base material, and alkali etching is performed on the inner peripheral surface of the sleeve. A cylinder sleeve characterized by plating after being treated. 2. A cylinder block for an internal combustion engine, wherein a sleeve made of an aluminum alloy is arranged in a cylinder body made of an aluminum alloy casting, wherein the aluminum alloy forming the sleeve contains silicon (Si); A cylinder block for an internal combustion engine, wherein the silicon (Si) is primary crystal silicon (Si) having an average particle diameter of 20 μm or less, and the inner peripheral surface of the sleeve is subjected to alkali etching treatment and then plated. 3. The cylinder block for an internal combustion engine according to claim 2, wherein silicon (Si) is contained in the aluminum alloy constituting the sleeve in an amount of 15 to 38% by weight. 4. The sleeve having an average particle size of 20 to 100 μm.
3. The cylinder block for an internal combustion engine according to claim 2, wherein m aluminum alloy powder is formed by coagulation and solidification.